Throttle return spring

[showcrop]

I have just reinstalled the dual carburetors on my antique car. With them I also installed new throttle return springs from the leading vendor of parts for this old car. My old springs, due to the pedal effort, seemed to be too strong especially when starting off going up hill. It doesn't seem right to me that the two springs take up only half of the distance between their mount points, so that they are stretched out pretty well with the throttles closed. What do you spring experts say? should they be stretching out to 3X their resting length when at full throttle? It doesn't seem right to me so I am thinking of installing some suitable lengthening wire.

 

[37 chief]

I think a weaker spring would work better. Stan

 

[Duner Wi]

I would start with lengthening wire first and then weaker springs if necessary.
On my old car I have a spring within a spring,that way if one breaks the other spring might do something.

 

[miangus]

Be careful having a throttle spring failure can be exciting. More so with cars that lock the steering when you shutoff the engine. A lot of throttle return springs have two softer springs one within the other.

 

[flying belgian]

Another option would be to stretch the springs.

 

[Janicholson]

Concentric springs, with reliable return tension are a great option. The angle of the spring in relation to the geometry of the throttle shaft/s lever/s can make a dramatic difference. Pulling from angled back toward the spring mount makes a progressive tension that is least at the initial tip in (automotive words) and progressively gets tighter toward full throttle. Where as if the arm is perpendicular, it is difficult at first then progressively easier. Not desirable. Jim

 

[pete 23]

Old mechanics trick to make a customer think he has more get up and go was to weaken the throttle
spring.

I would try weaker springs, longer or lighter.

 

[old-9]

I lost a spring one time. 65 Ford 352,3 on the tree, went around a corner and the peddle went to the floor. First gear in a city street. I shifted into second and shut it down coasted to curb. Drove home with a wire around the foot peddle, steering with left hand, pulling up on wire with right hand, girl friend shifting. Some things you never forget. joe

 

[Pete in MD]

miangus,

People shouldn't shut off the engine when that happens. Shift into neutral instead and keep your steering and brakes.

 

[rusty6]

(quoted from post at 20:02:30 02/16/22) miangus,

People shouldn't shut off the engine when that happens. Shift into neutral instead and keep your steering and brakes.

If they are like my old cars the steering and brakes work just the same running as shut off.

 

[miangus]

Your going to need a new motor if you try that. I had it happen with a 78 Z-28 with a warmed over 350, 70 LT-1 with a larger cam. It was my cousins car and they could not get it started, so they dropped it off at my place. I got it started , they had forgot to put the PCV valve in the line from the carb. I should have checked the return spring situation. When I took it for a test drive the spring came off when I shifted into 3rd gear. I tried to stall it with the brakes it initially slowed then over powered the brakes. I shut it off but the steering lock was just a bit off center, on the 78s there is no position between lock and on, I believe later locking steering systems had an off but not locked position. I kept turning it off to slow and on to steer.

 

[showcrop]

(quoted from post at 22:28:11 02/16/22)

(quoted from post at 20:02:30 02/16/22) miangus,

People shouldn't shut off the engine when that happens. Shift into neutral instead and keep your steering and brakes.

If they are like my old cars the steering and brakes work just the same running as shut off.

As does mine of course, LOL.

 

[Mike Groom]

You might want to try the double spring set-up that most parts stores offer,I think they were used on a lot of GM products,it is one spring inside of another,has worked well for me on many carbs. over the
years.